I have about (10) 80-photo slide trays with Ektachromes and Kodachromes but haven't looked at them with my slide projector in about 15 years. I have recently scanned about two trays of the 10 and find that they show well on a 52" HDTV with music in the background, dissolves, titles, etc. Actually I think they look better than with a slide projector. But my memory isn't s good as it use to be. I've even created video from them and posted on YouTube. I think they're more interesting in these other ways than straight slide projectors. Easier to set up too. Certainly easier to keep guests from bailing out to go home early when they see you setting up a slide projector. Now you just flip on the HDTV and start the show before they can make excuses why they got to go.
Of course that was all 35mm. I also have medium format. But these 6x7's were taken with Velvia 50 mainly. When I printed chemically, I had to do a 4x5 internegative. So I was really using negatives anyway. I recently did a roll of Portra 400 in 120 and it scans well. As long as some companies are making something, it should be OK. I guess there's nostalgia and most people don't like change or to see things they have had a relationship with disappear. But we all have to move on at times and we will survive.